1. Field of the Invention
The present invention relates to a side-exhaust heat dissipation module, and in particular to a side-exhaust heat dissipation module for effectively cooling a CPU on a main board.
2. Description of the Related Art
Referring to FIG. 1, the conventional heat dissipation module 1 is composed of a fan 2 and a heat sink 4 with plural fins 6 formed thereon. According to the heat flow simulation analysis as shown in FIG. 2, the conventional heat dissipation module 1 has the following drawbacks.
(1) The airflow from the fan 2 flows through the heat sink 4 and flows out via opposite sides of the fins 6. Obviously, there is no airflow passing through the central area A of the heat sink 4. Thus, the efficiency of thermal exchange in the central area A is very low. The heat generated by the CPU 8 is concentrated on the central area A of the heat sink 4 and the spindle 22 of the fan 2 is located above the central area A. Thus, there is no airflow flowing through the fins 6 in the central area A and the efficiency of heat dissipation of the conventional heat dissipation module 1 is enormously reduced.
(2) The heat sink 4 has a flat bottom and the airflow form the fan 2 flows downwardly to the flat bottom. Because of the short distance between the fan 2 and the heat sink 4 and the high density of the fins 6, the airflow is subject to a high back pressure. Thus, the amount of the airflow from the fan 2 is decreased and the efficiency of heat dissipation of the conventional heat dissipation module 1 is reduced.
Referring to FIG. 3, a conventional side-exhaust heat dissipation module 50 is provided to overcome the above problems. The fan 52 of the conventional side-exhaust heat dissipation module 50 is disposed on one side of the heat sink 54. The airflow from the fan 52 can flow through the heat sink 54 completely. The heat generated on the central area of the heat sink 54 can be guided to the fins 56 and dissipated to the atmosphere via thermal convection.
Referring to FIG. 4, in the conventional side-exhaust heat dissipation module 50, the lateral sides of the fins 56 adjacent to the fan 52 are vertical and the fins 56 are closely adjacent to the fan 52. A large central circulation zone B or a stagnation zone is formed in the front portion (the portion facing the fan 52) of the fins 56. In addition, because the airflow speeds in the upper and lower portions of the fins 56 are faster and the airflow speed in the central portion of the fins 56 is slower, the airflow distribution is not uniform across the fins 56. Thus, the efficiency of heat dissipation of the conventional side-exhaust heat dissipation module 50 is not enormously enhanced as compared to that of the conventional heat dissipation module 1.
Referring to FIG. 5, in order to solve the central circulation zone B or the non-airflow zone as mentioned above, an airflow guiding cover 58 is disposed on the fins 56 and the fan 52 is spaced from the fins 56 by a distance d such that a regulation zone exists between the fan 52 and the fins 56. Thus, the central circulation zone B of FIG. 4 is reduced to a central circulation zone Bxe2x80x2 and the airflow distribution across the fins 56 is more uniform.
Referring to FIG. 6, in order to further reduce or eliminate the central circulation zone, the fan 52 can be spaced from the fins 56 by a larger and preferred distance D.
Although the efficiency of heat dissipation of the conventional side-exhaust heat dissipation module 50 is enormously enhanced since the fan 52 is spaced from the fins 56 by a preferred distance D, the total volume of the conventional side-exhaust heat dissipation module 50 increases enormously as well, thus decreasing the useful inner space in the computer.
An object of the invention is to provide a side-exhaust heat dissipation module. The side-exhaust heat dissipation module comprises a base; a fan disposed on one side of the base; a fin assembly disposed on the base and composed of a plurality of parallel fins, the fin assembly having a concave end spaced from the fan by a predetermined distance; and an airflow guiding cover disposed on the fin assembly, wherein the airflow guiding cover is gradually expanded and extended from the fan to cover the fin assembly.
A detailed description will be given by the following embodiments with reference to the accompanying drawings.